Abnormal mucus clearance is an important contributor to the pathological phenotype of cystic fibrosis (CF). Our studies over the last decade have revealed that CF-related dysfunction of CFTR results in the dehydration of the airway mucus layer. The outcome of such dehydration is significant alterations in the biophysical properties of the mucus layer and its interaction with the cell surface, i.e. producing adherent mucus that sticks to epithelial cells and a slowing/failure of cilia- and cough-mediated mucus clearance. To understand the root causes of the pathology and develop effective therapies to treat such diseases, we must advance our knowledge of the fundamental mechanisms regulating mucus clearance. To this end, our laboratories have developed a series novel techniques to directly quantify a number of key biochemical and biophysical prosperities of the mucus layer, including mucin concentration, mucus osmotic pressure, mucus adhesion/cohesion strength, and mucus viscous and elastic moduli. We believe that novel approaches to quantifying biophysical processes in airway surface layer are critical to discern why mucus clearance fails in CF and to identify the optimal combinations of pharmacological agent(s) to restore/accelerate the rate of mucus clearance in patients with CF. Given the importance of the mucus layer in lung heath and its alteration in disease, the overarching goal of this the UNC Mucus Biochemistry and Biophysics Core is to provide Core users the ability to assess a variety of novel biochemical and biophysical properties of mucus. As detailed in this proposal, the Core will offer other investigators access to our specialized mucus/mucin assay, including measurements of: 1) absolute mucin concentrations by HPLC/light scattering and refractometry methods; 2) direct quantitation of mucins using immunologic and mass spectrometry approaches; 3) extracellular DNA concentration, a purported contributor of disease progression in CF; 4) gravimetric measurements of mucus percent solids; 5) total and partial mucus osmotic pressure; 6) mucus/cell surface adhesion forces; 7) mucus cohesive strength; 8) bulk mucus rheology; 9) small-scale micro-bead rheology; 10) rates of cilia-mediated mucus clearance; and 11) rates of cough-mediated mucus clearance. The UNC mucus screening core is uniquely positioned to both: 1) characterize the properties of user supplied mucus samples as well as 2) assess the impact of investigator supplied candidate therapeutic agents on these biochemical/biophysical properties. The strength of this Core is the collaboration of a number of scientists who are experts in the field of mucus/mucin analysis. The benefits to potential Core users include advice from Core Center Investigators as to how to answer mucus specific questions and the ability to generate data utilizing our novel techniques. The ultimate goal of the UNC Mucus Biochemistry and Biophysics Core is to free up individual investigators to focus on basic science and drug development.